Selective inhibition of distracting input

Abstract

We review a series of studies exploring distractor suppression. It is often assumed that preparatory distractor suppression is controlled via top-down mechanisms of attention akin to those that prepare brain areas for target enhancement. Here, we consider two alternative mechanisms: secondary inhibition and expectation suppression within a predictive coding framework. We draw on behavioural studies, evidence from neuroimaging and some animal studies. We conclude that there is very limited evidence for selective top-down control of preparatory inhibition. By contrast, we argue that distractor suppression often relies secondary inhibition of non-target items (relatively non-selective inhibition) and on statistical regularities of the environment, learned through direct experience.

Inhibition in selective attention

“…One recent proposal is that this form of learned inhibition relies on expectation suppression, consistent with predictive processing models, that have recently gained a lot of scientific traction and stature . In these models, the brain continuously generates predictions about incoming sensory input based on learned regularities in the environment, and what is being fed up the hierarchy is not sensory input per se, but rather the mismatch between the brain's a priori predictions and the incoming input, or so‐called prediction errors.…”

“…In contrast to the notion of direct working memory–based distractor suppression, it has also been suggested that suppression of distracting information may rely on mechanisms that render the representation of the target in working memory maximally distinct from that of the distractor, thereby indirectly decreasing the chance of distractor selection . In yet another account, distractor inhibition may bypass representation in working memory altogether, relying on expectation‐dependent suppression . Below, we discuss these different accounts of preparatory inhibition in more detail in light of the empirical literature to address the outstanding question if distractor inhibition can be implemented in advance, and if so, how and under what conditions?…”

“…However, as also pointed out recently by Foster and Awh, evidence in support of the notion that alpha oscillations implement active, top‐down distractor suppression is ambiguous. That is, the vast majority of attention studies reporting increased preparatory alpha activity over irrelevant visual regions used task designs in which foreknowledge about the distractor location or features was accompanied by foreknowledge about the target location or features, such as bilateral displays, rendering it possible that observed effects could also simply reflect attending away or secondary inhibition related to attention to the target . The same is true for studies that used cues that signaled the likelihood of upcoming distraction, but also provided information about the upcoming target, and examined changes in other measures of preparatory activity, such as the cue‐evoked LDAP ERP component …”

“…In this, we dissociate between proposed preparatory mechanisms that suppress distractor features in advance and suppressive mechanisms that come about in response to distracting sensory input . While the long‐standing view has been that inhibition of distracting or irrelevant sensory information is under direct, volitional control similar to attention to goal‐relevant aspect of the environment, it is becoming increasingly clear that suppression is not under direct top‐down control and can be implemented via a multitude of underlying mechanisms, each tuned to specific circumstances . Recent behavioral studies, for example, have shown that the ability to ignore distracting information often strongly depends on learning based on previous experiences with the distracting information .…”

“…Recent behavioral studies, for example, have shown that the ability to ignore distracting information often strongly depends on learning based on previous experiences with the distracting information . Yet, what factors determine the ability to inhibit distractor information and which specific set of neural mechanisms arise under different circumstances remain topics of active debate …”